1. Field of the Invention
The present invention relates to a technique for automatically changing a digital video disc (DVD) for play back in a DVD-video playback apparatus that stores a plurality of DVD discs and has a disc-change function for selectively playing back one of the DVD discs.
2. Description of the Related Art
CD changers that store a plurality of CD digital audio (CD-DA) discs on which audio presentations (music, etc.) are recorded as tracks and sequentially play back the tracks recorded on each CD-DA disc are known in the art. In a typical CD changer, automatic disc changing is performed by successively playing back the tracks recorded on each CD-DA disc from the first track to the last track. When the playback of the last track of one of the CD-DA discs is completed, it is determined that the playback of this CD-DA disc is completed, and this CD-DA disc is changed for the next CD-DA disc.
On the other hand, DVD discs are commonly used for recording video presentations. In DVD discs, video presentations are generally recorded as titles. In addition, unlike CD-DA discs where a default playback order of the audio presentations is defined by the order in which the tracks are recorded, providers of DVD discs can arbitrarily set the playback sequence of the titles. Therefore, the order in which the titles are recorded and title numbers which are assigned to the titles do not always correspond to the playback order of the titles. In addition, a playback sequence where a title is repeatedly and endlessly played back or a playback sequence where the title to be played back next is determined by an operation performed by a user every time the playback of a title is completed may also be used. Accordingly, in such cases, the last title, which corresponds to the last track in CD-DA discs, is not defined in DVD discs.
Accordingly, the above-described automatic disc change technique for CD changers, in which it is determined that the playback of a CD-DA disc is completed when the playback of the last track is completed and this CD-DA disc is changed for the next CD-DA disc, cannot be applied to DVD discs by simply replacing tracks with titles. In known DVD-video playback apparatuses which store a plurality of DVD discs and which have a disc-change function for selectively playing back one of the DVD discs, automatic disc changing for automatically changing the DVD disc to be played back cannot be performed. More specifically, when a plurality of DVD discs are used, the user must determine whether or not to change the DVD disc to be played back and perform an operation for changing the DVD disc.